ALX: a program that multiplies two numbers.

[ahmed149]

include

include

/**

• main - Prints the multiplication of two numbers, followed by a new line.
• @argc: The number of arguments supplied to the program.
• @argv: An array of pointers to the arguments.
• Return: If the program receives two arguments - 0.

• If the program does not receive two arguments - 1. / int main(int argc, char argv[]) { int num1, num2, prod;

  if (argc != 3) { printf("Error\n"); return (1); }

  num1 = atoi(argv[1]); num2 = atoi(argv[2]); prod = num1 * num2;

  printf("%d\n", prod);

  return (0); }

[ahmed149]

gcc -Wall -pedantic -Werror -Wextra -std=gnu89 3-mul.c -o mul

[ahmed149]

Of course, I'll explain the program step by step without giving you code and provide additional examples as requested.

This program is a C program that multiplies two numbers and prints the result. Here's a breakdown of what's happening:

1. int main(int argc, char *argv[]):

   • argc stands for "argument count," and it tells you how many arguments (pieces of information) were given to the program when you run it.
   • argv stands for "argument vector" and is an array of strings (text) that contains those arguments.

2. if (argc != 3):

   • This condition checks whether the program received exactly three arguments. In C, the program name itself is counted as an argument (so argc is at least 1). Therefore, when you want two additional arguments for multiplication, you check if argc is not equal to 3.

3. printf("Error\n");:

   • If the condition in the previous step is true (meaning the program didn't receive two additional arguments), it prints an error message.

4. return (1);:

   • After printing the error message, the program exits with a return value of 1. This typically indicates that something went wrong.

5. num1 = atoi(argv[1]); and num2 = atoi(argv[2]);:

   • These lines convert the text (strings) from argv[1] and argv[2] into integer numbers. atoi is a function that does this conversion.

6. prod = num1 * num2;:

   • Here, it calculates the product of the two numbers.

7. printf("%d\n", prod);:

   • Finally, it prints the product of the two numbers.

So, to summarize:

• The program checks if it received exactly three arguments (including the program name).
• If not, it prints an error message and returns 1 to indicate an error.
• If it received three arguments, it multiplies the second and third arguments (converted from strings to integers) and prints the result.

For example:

• If you run the program with ./program 5 7, it will print 35, which is the result of 5 multiplied by 7.
• If you run it with fewer or more than three arguments, it will print "Error" and return 1.

I hope this explanation helps! If you have more questions or need further examples, feel free to ask.